This invention relates to work gloves, and more particularly to gloves designed to attenuate the vibration encountered in using tools.
Various hand held tools and pieces of machinery are sources of substantial amounts of vibration during use. Such tools include power saws and drills, rivet guns, jack hammers, and any number of similar tools. Extensive use of such equipment may result in injury to the human user and significant disability.
Protective gloves have been proposed to shield the user from these effects. However, prior art gloves do not completely solve the problem. It has been found that currently available gloves in fact do not adequately attenuate applied vibration. In addition, it has been found that increasing the amount of vibration dampening material in currently available gloves to the point where attenuation is adequate results in a glove which is so thick or bulky that manipulation and control of hand tools is significantly impaired. In addition, such gloves tend to be uncomfortable for the user.
Although most of the vibration is transmitted to the user through the user's palm, it is also necessary to protect the user's fingers from vibration. The problems of bulkiness and control are, of course, accentuated in trying to shield the fingers from vibration.
The European Committee for Standardization has enacted certain standards for antivibration gloves to address the problems addressed above, but it is not believed that any prior art gloves meet the standard without increasing the amount of vibration dampening material so much as to severely hinder the manipulation and control of the glove. This standard, CEN/231/3 N70E, provides for measuring the transmissibility (or alternatively, the attenuation) of vibration in two different frequency ranges under conditions specified in the standard. In the lower frequency range, from 31.5-200 Hz, the transmissibility may not exceed 1.0. Thus, in this range the gloves are not allowed to amplify vibration. In the higher frequency range, from 200 Hz to 1250 Hz, the transmissibility must be less than 0.6 (i.e., at least 40% attenuation). That is, in the higher range, the gloves must reduce vibration to 60% or less of the level measured when the operator is not wearing gloves. This standard is hereby incorporated herein by reference, including the testing procedure set forth therein. It should be understood that whenever the term "transmissibility" or its converse "attenuation" is used herein, it is intended that such be measured in accordance with the aforementioned standard.